Amp Size for Bi-Amping

[Morgan]

Hi, I have a Monoprice 7X200 that I'm powering 5 JBL ES-100 and 2 smaller JBL Bookshelf speakers for the rear channels. I also have a Emotiva XMC-1.2 Processor. I was wondering what size Amp. you would suggest to Bi-Amp the 5 ES-100s? Thanks!

[mgbpuff]

I would think you would simply buy another Monoprice 7x200. The amps should be identical since the internal speaker crossovers are not bypassed without tearing the speakers apart. This type of bi-amping is called passive bi-amping vs active biamping which replaces the speaker's crossover circuitry with a programmed crossover allowing different amps to be used.

[Morgan]

I was hoping to save a few bucks and get an Amp with less power (100X5 for example) and let the processor with Dirac make the necessary corrections / compensations.

[PaulBe]

Mar 6, 2024 13:56:43 GMT -5 Morgan said:

I was hoping to save a few bucks and get an Amp with less power (100X5 for example) and let the processor with Dirac make the necessary corrections / compensations.

You have the same sensitivity at your respective hi-pass and low-pass speaker terminals.  Dirac will not correct a level mismatch between hi-pass and low-pass. Equal amps have the same input sensitivity and the same output gain, which is what a passive bi-amping/bi-wiring scheme wants to see.

The only way to compensate for what you want to do with different amps, is to have at least input sensitivity controls, And perhaps output gain controls, on your amps. Few consumer amps have these controls.

I'm assuming your Hi/Lo split is at 450Hz - the crossover frequency for Woof to Mid-and-above. Just use the same amps, or run full range with one amp. This passive bi-amping is not real bi-amping.  The full range signal still goes to each amp input.  Performance gains are likely to be more imaginary than real.

[brubacca]

You could buy any other amp and use it for your rear channel speakers. Then use 4 channels of your monoprice for the JBL ES 100 speakers. Then you have identical amps for your front L/R speakers and you can get a low wattage amp for your bookshelf.

I did this with a 5 channel amp years ago to bi-amp my front L/R in my HT. Can't say I ever felt it made a difference. Although being a glutton for punishment since I have the cables and amp I may do it again.

[leonski]

So much to cover!
First? Are there 4 speaker binding posts on the back of each speaker.....connected by jumpers?

If so? Continue.

Next? When you remove the jumpers? You now have basically 2 speakers per enclosure. Where is the crossover? The ES100 is a 3-way speaker, so 2 crossover points.
A lower one will put power only to the woofer the higher frequency cross will be between the mid and tweeter.
90% chance that the crossover is woofer / mid-tweet.......And given that it's a fairly low frequency, it would indicate that you need ABOUT as much power for the lows as for th
mid-tweet.
Brubacca has a good point! and makes good use of existing equipment.

What are you trying to fix or improve? Are you asking Too Much from the ES100s?

[mgbpuff]

Mar 6, 2024 17:14:44 GMT -5 brubacca said:

You could buy any other amp and use it for your rear channel speakers. Then use 4 channels of your monoprice for the JBL ES 100 speakers. Then you have identical amps for your front L/R speakers and you can get a low wattage amp for your bookshelf.

I did this with a 5 channel amp years ago to bi-amp my front L/R in my HT. Can't say I ever felt it made a difference. Although being a glutton for punishment since I have the cables and amp I may do it again.

The man said he has 5 JBL-ES100 speakers he wants to bi-amp so he needs a total of 12 channels to do everything he wants to do.

[leonski]

Still need to figure out the final goal.
If speakers are in 6000 cubic feet? MIght have wrong speaker.
JBL has some high power cautions, which should be taken into account when adding amps.

Is the Monoprice the same as the ATI amp? If so? I see a 20 amp fuse and 15 amp service for the 7 channel version.


IF the OP goes ahead with his project, he should also budget for additional dedicated outlets. And I'd make 'em 12ga / 20 amp.....

[mgbpuff]

One step at a time. If the present volume level is adequate, two amps will draw only a very small amount of additional power. If you turn on the two amps simultaneously via a trigger circuit and that trips the breaker, then just remove the trigger wire and turn them on manually or, if you must turn them on simultaneously, it may be possible to get a C trip or D trip replacement circuit breaker of the same current rating that tolerates more inrush but protects at the same steady state current level as your present breaker (check local code). Same is true with fuses. If you like the sound now in your room regardless of room size, nothing will change with adding an additional amp except maybe a little more bottom end thump.

[PaulBe]

Mar 7, 2024 9:11:29 GMT -5 mgbpuff said:

One step at a time. If the present volume level is adequate, two amps will draw only a very small amount of additional power. If you turn on the two amps simultaneously via a trigger circuit and that trips the breaker, then just remove the trigger wire and turn them on manually or, if you must turn them on simultaneously, get a motor circuit type circuit breaker of the same current rating that tolerates more inrush but protects at the same steady state current level as your present breaker. Same is true with fuses. If you like the sound now in your room regardless of room size, nothing will change with adding an additional amp except maybe a little more bottom end thump.

Until recently, I ran the whole system off one 15 amp breaker, and two 15 amp power strips. One power strip had the low level electronics attached. One power strip had the amps attached. I powered on all 5 QSC PLD amps with the 15 amp power strip switch, at the same time, with no breaker or power strip problems. The QSC amps do have a 'slow start'.  A running current load at high speaker volumes was minimally more than the quiescent load - about 5-10% more current, on average, for all 20 channels.

[KeithL]

I want to offer a bit of clarification here...

First of all you are correct in saying that Dirac Live cannot fully "correct" or "compensate" for differences in sensitivity between the two amps.
What Dirac Live will "see" is a "step" - where the output level "jumps up" or "drops down" at some particular frequency.
When you "passively bi-amp" you are still using crossovers, which are never "dead sharp", so there will still be some "overlap", and this "step" will be somewhat gradual.
Dirac Live will then ATTEMPT to compensate for or correct this.

In effect, Dirac Live will "see" what seems to be a speaker with a somewhat poorly designed crossover, and a significantly uneven frequency response.
This will "make Dirac Live work harder" and make it less likely that you will get as good of a result.
So... NOT a good idea.

HOWEVER, the issue here is GAIN (sensitivity) rather than power.
So all you need to ensure is that the gain is the same on both amplifiers or amplifier channels.
So, for example, ALL of our current models of POWER AMP have a fixed gain of 29 dB... so the same.
And MANY other consumer power amps that have a fixed gain will have a gain of somewhere between 29 dB and 32 dB.
HOWEVER, for a variety of other reasons as well, it almost always works out best to use two similar amplifiers, or amplifier channels, for the two halves of a single speaker.
(Different amplifiers have other characteristics that are different which can result in a less-than-smooth transition between them.)

If you are mixing SIMILAR amps... like using two different of our BasX amps for the two halves of a speaker, there would be no problem.
This would be true because both would have the same GAIN, and very similar topologies, even if they had different maximum power outputs. 
(So they would both have the same gain and also "sound very much the same"...)

Also note that, while it's not always true, it is generally agreed that, with MOST speakers that offer bi-amp terminals, the power requirements for the two halves would be relatively similar.
There would be some argument for using a bigger amp on the low end if the speaker is a big front being run full range... but probably not otherwise.

HOWEVER...
If you're running a pair of big speakers...
There is generally NO BENEFIT to bi-amping with two 100 watt/channel amps, rather than using one 200 watt/channel amp, and the single amp will probably cost less.
(The fact that a lot of big speaker include those terminals is more because people ask for them than because it will actually provide any sort of audible improvement.)
(They're kind of a "leftover" from when "big amps" were expensive; and from when getting a smaller amp to clip a bit more gracefully was considered a useful benefit.)
(The only real reason I can see for doing this would be to "up the power" by adding a second identical amplifier to an existing one that's driving a pair of big speakers.)

Mar 6, 2024 14:44:58 GMT -5 PaulBe said:

Mar 6, 2024 13:56:43 GMT -5 Morgan said:

I was hoping to save a few bucks and get an Amp with less power (100X5 for example) and let the processor with Dirac make the necessary corrections / compensations.

You have the same sensitivity at your respective hi-pass and low-pass speaker terminals.  Dirac will not correct a level mismatch between hi-pass and low-pass. Equal amps have the same input sensitivity and the same output gain, which is what a passive bi-amping/bi-wiring scheme wants to see.

The only way to compensate for what you want to do with different amps, is to have at least input sensitivity controls, And perhaps output gain controls, on your amps. Few consumer amps have these controls.

I'm assuming your Hi/Lo split is at 450Hz - the crossover frequency for Woof to Mid-and-above. Just use the same amps, or run full range with one amp. This passive bi-amping is not real bi-amping.  The full range signal still goes to each amp input.  Performance gains are likely to be more imaginary than real.

[PaulBe]

Mar 7, 2024 11:29:33 GMT -5 KeithL said:

I want to offer a bit of clarification here...

First of all you are correct in saying that Dirac Live cannot fully "correct" or "compensate" for differences in sensitivity between the two amps.
What Dirac Live will "see" is a "step" - where the output level "jumps up" or "drops down" at some particular frequency.
When you "passively bi-amp" you are still using crossovers, which are never "dead sharp", so there will still be some "overlap", and this "step" will be somewhat gradual.
Dirac Live will then ATTEMPT to compensate for or correct this.

In effect, Dirac Live will "see" what seems to be a speaker with a somewhat poorly designed crossover, and a significantly uneven frequency response.
This will "make Dirac Live work harder" and make it less likely that you will get as good of a result.
So... NOT a good idea.

HOWEVER, the issue here is GAIN (sensitivity) rather than power.
So all you need to ensure is that the gain is the same on both amplifiers or amplifier channels.
So, for example, ALL of our current models of POWER AMP have a fixed gain of 29 dB... so the same.
And MANY other consumer power amps that have a fixed gain will have a gain of somewhere between 29 dB and 32 dB.
HOWEVER, for a variety of other reasons as well, it almost always works out best to use two similar amplifiers, or amplifier channels, for the two halves of a single speaker.
(Different amplifiers have other characteristics that are different which can result in a less-than-smooth transition between them.)

If you are mixing SIMILAR amps... like using two different of our BasX amps for the two halves of a speaker, there would be no problem.
This would be true because both would have the same GAIN, and very similar topologies, even if they had different maximum power outputs. 
(So they would both have the same gain and also "sound very much the same"...)

Also note that, while it's not always true, it is generally agreed that, with MOST speakers that offer bi-amp terminals, the power requirements for the two halves would be relatively similar.
There would be some argument for using a bigger amp on the low end if the speaker is a big front being run full range... but probably not otherwise.

HOWEVER...
If you're running a pair of big speakers...
There is generally NO BENEFIT to bi-amping with two 100 watt/channel amps, rather than using one 200 watt/channel amp, and the single amp will probably cost less.
(The fact that a lot of big speaker include those terminals is more because people ask for them than because it will actually provide any sort of audible improvement.)
(They're kind of a "leftover" from when "big amps" were expensive; and from when getting a smaller amp to clip a bit more gracefully was considered a useful benefit.)
(The only real reason I can see for doing this would be to "up the power" by adding a second identical amplifier to an existing one that's driving a pair of big speakers.)

Mar 6, 2024 14:44:58 GMT -5 PaulBe said:

...

I wish manufacturers would stop putting these dual passive-bi-amp jacks on speakers. It creates more confusion than solutions.

I was trying to keep things simple while following what the OP wants to do. Perhaps I made things more difficult.

~~~

To Morgan: I would skip the whole bi-amp thing. If you want more power, use 4 channels of your current multi-channel amp for the 4 surrounds, and buy new better monoblocks or a three channel amp for the LCR. IIRC, Emotiva has some very nice hi-end monoblocks and three channel amps. 

You will have more than enough power for the surrounds without bi-amping. Put the money where it counts in the LCR.

Remember that an amplifier is a linear device. It's neither a compressor nor an expander. As long as you can equalize levels between channels, sensitivity and gain will not be an issue.

[KeithL]

Perfect !

(And, yeah, we put them there because people ask... we NEVER use them.)

Mar 7, 2024 14:15:41 GMT -5 PaulBe said:

Mar 7, 2024 11:29:33 GMT -5 KeithL said:

I want to offer a bit of clarification here...

First of all you are correct in saying that Dirac Live cannot fully "correct" or "compensate" for differences in sensitivity between the two amps.
What Dirac Live will "see" is a "step" - where the output level "jumps up" or "drops down" at some particular frequency.
When you "passively bi-amp" you are still using crossovers, which are never "dead sharp", so there will still be some "overlap", and this "step" will be somewhat gradual.
Dirac Live will then ATTEMPT to compensate for or correct this.

In effect, Dirac Live will "see" what seems to be a speaker with a somewhat poorly designed crossover, and a significantly uneven frequency response.
This will "make Dirac Live work harder" and make it less likely that you will get as good of a result.
So... NOT a good idea.

HOWEVER, the issue here is GAIN (sensitivity) rather than power.
So all you need to ensure is that the gain is the same on both amplifiers or amplifier channels.
So, for example, ALL of our current models of POWER AMP have a fixed gain of 29 dB... so the same.
And MANY other consumer power amps that have a fixed gain will have a gain of somewhere between 29 dB and 32 dB.
HOWEVER, for a variety of other reasons as well, it almost always works out best to use two similar amplifiers, or amplifier channels, for the two halves of a single speaker.
(Different amplifiers have other characteristics that are different which can result in a less-than-smooth transition between them.)

If you are mixing SIMILAR amps... like using two different of our BasX amps for the two halves of a speaker, there would be no problem.
This would be true because both would have the same GAIN, and very similar topologies, even if they had different maximum power outputs. 
(So they would both have the same gain and also "sound very much the same"...)

Also note that, while it's not always true, it is generally agreed that, with MOST speakers that offer bi-amp terminals, the power requirements for the two halves would be relatively similar.
There would be some argument for using a bigger amp on the low end if the speaker is a big front being run full range... but probably not otherwise.

HOWEVER...
If you're running a pair of big speakers...
There is generally NO BENEFIT to bi-amping with two 100 watt/channel amps, rather than using one 200 watt/channel amp, and the single amp will probably cost less.
(The fact that a lot of big speaker include those terminals is more because people ask for them than because it will actually provide any sort of audible improvement.)
(They're kind of a "leftover" from when "big amps" were expensive; and from when getting a smaller amp to clip a bit more gracefully was considered a useful benefit.)
(The only real reason I can see for doing this would be to "up the power" by adding a second identical amplifier to an existing one that's driving a pair of big speakers.)

I wish manufacturers would stop putting these dual passive-bi-amp jacks on speakers. It creates more confusion than solutions.

I was trying to keep things simple while following what the OP wants to do. Perhaps I made things more difficult.

~~~

To Morgan: I would skip the whole bi-amp thing. If you want more power, use 4 channels of your current multi-channel amp for the 4 surrounds, and buy new better monoblocks or a three channel amp for the LCR. IIRC, Emotiva has some very nice hi-end monoblocks and three channel amps. 

You will have more than enough power for the surrounds without bi-amping. Put the money where it counts in the LCR.

Remember that an amplifier is a linear device. It's neither a compressor nor an expander. As long as you can equalize levels between channels, sensitivity and gain will not be an issue.

[Morgan]

Thanks to everyone who responded to my post. It sounds to me like the increase in sound quality would be minimal if any and I could be 'screwing" things up big time if I do it wrong. I think I'm going to go with Keith's suggestion and forget about bi-amping my ES-100s. Maybe King Crab legs would be a better upgrade!
Thanks again to all!

[leonski]

I see you are a Florida resident.

I'd get a whole house surge protector.

I lived in Tampa (USF) and N.Miami where I graduated from HS....

Spent time in Wachula, Arcadia, Zolfo Springs. A friend had an EARLY Sony receiver which

easily got Mt. Dora from Tampa......Which is a 'high point' in the state.....

[leonski]

Elliot Sound Products article conceringing ACTIVE biamp......That is? Where the frequency is divided prior to the amps and is distributed than.
Speaker level crossover is mostly deleted....except maybe the mid-tweet.......
Passive has none of the advantages of 'Active'...where each amp gets the full 20->20.......and it is manipulated at the speaker level.

sound-au.com/bi-amp.htm

Morgan? I think you are in range of Tampa. Head over to YBOR City for dinner at the Colombia. I hope it is still 'good'.
But pack some heat. Crime Rate in about 300% the national average. And you can't get a locally wrapped Cigar, any more.

Early 70's?? I'd go to the Perfecto Garcia plant and pick up a box of Cigarellos.....freshly rolled....

[vcautokid]

Well Keith is spot on. Frankly, you can do more with other things that will make a profound difference. Notice I said difference.

Room treatment, speaker placement. DIRAC is great. But no room correction is a panacea. I don't care how amazing it is. Put your money where your room is. Might not be expensive to do. Optimization of the room with speakers and Subwoofer(s), is a benefit that is real, and counts for more than just more power.

Once a room is properly setup, DIRAC, MAAC, Auddisey, and so on can do its job more effectively. Nobody wants to talk about because muscle is more fun than tuning.

DIRAC offers up excellent baseline tuning. But are you happy with it? Don't know. Most systems offer up presets for further tweaking to the way you want.

Have you optimized your DIRAC curves. Do you have the latitude in there to do it? Or is your room so out of shape, it maxed all of your settings to compensate, and it still isn't right.

Maybe your room is fine, maybe there is still more to do. Don't know.

But I had to throw this out there.

Had a friend do room tuning along with all the same gear. It sounds amazing. He had a professional help him, but it was all worth it. He enjoys his gear and speakers more, and added a streamer too, and the listening is far better than adding any one component could profoundly do. It's fundamentals. Not power.

[PaulBe]

Mar 10, 2024 4:26:16 GMT -5 vcautokid said:

Well Keith is spot on. Frankly, you can do more with other things that will make a profound difference. Notice I said difference.

Room treatment, speaker placement. DIRAC is great. But no room correction is a panacea. I don't care how amazing it is. Put your money where your room is. Might not be expensive to do. Optimization of the room with speakers and Subwoofer(s), is a benefit that is real, and counts for more than just more power.

Once a room is properly setup, DIRAC, MAAC, Auddisey, and so on can do its job more effectively. Nobody wants to talk about because muscle is more fun than tuning.

DIRAC offers up excellent baseline tuning. But are you happy with it? Don't know. Most systems offer up presets for further tweaking to the way you want.

Have you optimized your DIRAC curves. Do you have the latitude in there to do it? Or is your room so out of shape, it maxed all of your settings to compensate, and it still isn't right.

Maybe your room is fine, maybe there is still more to do. Don't know.

But I had to throw this out there.

Had a friend do room tuning along with all the same gear. It sounds amazing. He had a professional help him, but it was all worth it. He enjoys his gear and speakers more, and added a streamer too, and the listening is far better than adding any one component could profoundly do. It's fundamentals. Not power.

These passive bi-amp connections need to go away. they don't address real problems.

Very high power (high output voltage) amps are rarely needed in a home setting - been there and done that. They can be fun, like dropping a turbo'd V8 into a Corvair,,, but won't add much, or anything, to real system performance at any reasonable volume. The analogy isn't precise, because additional output current capability is valuable into a reactive load. Some inefficient loads may need more voltage output along with more current output.

The most important performance of an amplifier is in the 'first watt'. Quality first; then quantity if necessary.

[mgbpuff]

Using a more powerful amp than what one might deem absolutely necessary, may pay dividends in dynamic range (if the source supports wide dynamics) which can add to the sense of realism. Of course, the speakers are a big part of this equation also. People seem to be very tolerant of compressed music whether it is compressed at mastering or compressed by modest amplification and speaker performance. Audiophiles want music to get as realistic sounding as possible. There's no one answer for all combinations of environment, equipment, and desires.

[PaulBe]

Mar 10, 2024 15:11:20 GMT -5 mgbpuff said:

Using a more powerful amp than what one might deem absolutely necessary, may pay dividends in dynamic range (if the source supports wide dynamics) which can add to the sense of realism. Of course, the speakers are a big part of this equation also. People seem to be very tolerant of compressed music whether it is compressed at mastering or compressed by modest amplification and speaker performance. Audiophiles want music to get as realistic sounding as possible. There's no one answer for all combinations of environment, equipment, and desires.

A more efficient speaker may pay dividends in dynamic range. Unclipped modest power or high power amplifiers with similar circuitry, driven to the same level, produce the same dynamic range, into the same load. A low power amplifier with the 'right stuff' can sound better than a high power amplifier - power supply, first watt quality, reasonable damping difference, output current capability... High power with(because of) higher voltage rails means nothing by itself.

An amplifier is a liner device. The higher power amplifier can produce more unclipped volume, but, as more power is consumed by the speaker, the speaker becomes more of a compressor. ALL speakers begin to compress at relatively low power inputs. High power input to any real speaker, and more excursion, creates more compression.

The first key to realistic dynamic range is speaker efficiency.

Check out pro driver sites. Compression specs for various input power are often listed. You won’t see this spec for any consumer speaker. You can also see this graphically in some of the Klippel data for drivers.

The most dynamic speaker is one that consumes no power when playing.  They don't exist.  Some get closer than others.

The most dynamic amplifier is one that remains in 'stasis' regardless the load.  Hmmm... where have we seen that term before.